<%@ page contentType="text/html; charset=UTF-8" isErrorPage="true" isELIgnored="false" pageEncoding="UTF-8"
         import="java.util.*" %>
<%--<%@ include file="demo.jsp"%>--%>
<%--<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>--%>
<!DOCTYPE html>
<html>
<head>
    <title>JSP - Hello World</title>
</head>
<body>
<h1>


    <%--    ${pageContext}--%>
    ${pageContext.request}

    ${pageScope}
    <%--首先pagescope -> requestscope -> sessionscope -> applicationscope--%>
    ${applicationScope.msg}
    ${requestScope.msg}
    <%--    ${msg}--%>

    ${a + b}

    ${empty requestScope.msg}

    <%--        ${?:}--%>

    <%--out.print('Hello world')--%>
    <%--<%=
    request.getAttribute("msg") == null ? "" : request.getAttribute("msg")
    %>--%>

    <%--    <%
            request.getAttribute("msg");

            session.setAttribute("","");

            application.getRealPath("");

            config.getInitParameter("");
        %>--%>

    <%--    <jsp:forward page="demo.jsp"/>


        <%= "Hello World!" %>


        <%!
            int age = 20;

            public void test() {

            }

            class InnerA {

            }


            static class InnerB {

            }

        %>

        <%

            System.out.println("hello jsp");

            int x = 10;

            System.out.println(x);

            class InnerC {


            }

        %>

        <%=1
        %>--%>


</h1>
<br/>
</body>
</html>